This invention is in the field of soybean breeding, specifically relating to a soybean variety designated 91B03.
The present invention relates to a new and distinctive soybean variety, designated 91B03 which has been the result of years of careful breeding and selection as part of a soybean breeding program. There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possess the traits to meet the program goals. The goal is to combine in a single variety an improved combination of desirable traits from the parental germplasm. These important traits may include higher seed yield, resistance to diseases and insects, tolerance to drought and heat, and better agronomic qualities.
Field crops are bred through techniques that take advantage of the plant""s method of pollination. A plant is self-pollinated if pollen from one flower is transferred to the same or another flower of the same plant. A plant is sib-pollinated when individuals within the same family or variety are used for pollination. A plant is cross-pollinated if the pollen comes from a flower on a different plant from a different family or variety. The terms xe2x80x9ccross-pollinationxe2x80x9d and xe2x80x9cout-crossxe2x80x9d as used herein do not include self-pollination or sib-pollination. Soybean plants (Glycine max), are recognized to be naturally self-pollinated plants which, while capable of undergoing cross-pollination, rarely do so in nature. Insects are reported by some researchers to carry pollen from one soybean plant to another and it generally is estimated that less than one percent of soybean seed formed in an open planting can be traced to cross-pollination, i.e. less than one percent of soybean seed formed in an open planting is capable of producing F1 hybrid soybean plants, See Jaycox, xe2x80x9cEcological Relationships between Honey Bees and Soybeans,xe2x80x9d appearing in the American Bee Journal Vol. 110(8): 306-307 (August 1970). Thus intervention for control of pollination is critical to establishment of superior varieties.
A cross between two different homozygous varieties produces a uniform population of hybrid plants that may be heterozygous for many gene loci. A cross of two plants that differ at a number of gene loci will produce a population of hybrid plants that differ genetically and will not be uniform. Regardless of parentage, plants that have been self-pollinated and selected for type for many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny.
Soybeans, (Glycine max), can be bred by both self-pollination and cross-pollination techniques. Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of variety used commercially (e.g., F1 hybrid variety, pureline variety, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection.
Soybean plant breeding programs combine the genetic backgrounds from two or more lines, varieties or various other germplasm sources into breeding populations from which new lines or varieties are developed by selfing and selection of desired phenotypes. Plant breeding and variety, line or hybrid development, as practiced in a soybean plant breeding program developing significant genetic advancement, are expensive and time consuming processes.
Mutation breeding is one of the many methods of introducing new traits into soybean varieties. Mutations that occur spontaneously or are artificially induced can be useful sources of variability for a plant breeder. The goal of artifical mutagenesis is to increase the rate of mutation for a desired characteristic. Mutation rates can be increased by many different means including temperature, long-term seed storage, tissue culture conditions, radiation; such as X-rays, Gamma rays (e.g. cobalt 60 or cesium 137), neutrons, (product of nuclear fission by uranium 235 in an atomic reactor), Beta radiation (emitted from radioisotopes such as phosphorus 32 or carbon 14), or ultraviolet radiation (preferably from 2500 to 2900nm), or chemical mutagens (such as base analogues (5-bromo-uracil), related compounds (8-ethoxy caffeine), antibiotics (streptonigrin), alkylating agents (sulfur mustards, nitrogen mustards, epoxides, ethylenamines, sulfates, sulfonates, sulfones, lactones), azide, hydroxylamine, nitrous acid, or acridines. Once a desired trait is observed through mutagenesis the trait may then be incorporated into existing germplasm by traditional breeding techniques. Details of mutation breeding can be found in xe2x80x9cPrincipals of Cultivar Developmentxe2x80x9d Fehr, 1993 Macmillan Publishing Company the disclosure of which is incorporated herein by reference.
Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of variety used commercially (e.g., F1 hybrid variety, pureline variety, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection.
The complexity of inheritance influences choice of the breeding method. In general breeding starts with the crossing of two genotypes, each of which may have one or more desirable characteristics that is lacking in the other or which complements the other. If the two original parents do not provide all the desired characteristics, other sources can be included by making more crosses. In each successive filial generation, superior plants are selected and self-pollinated which increases the homozygosity of the varieties. Typically in a breeding program five or more successive filial generations of selection and selfing are practiced: F1xe2x86x92F2; F2xe2x86x92F3;F3xe2x86x92F4; F4xe2x86x92F5, etc. After a sufficient amount of inbreeding, successive filial generation will serve to increase seed of the developed variety. Preferably, a developed variety comprises homozygous allele at about 95% or more of its loci.
Pedigree breeding is commonly used for the improvement of self-pollinating crops. Two parents that possess favorable, complementary traits are crossed to produce an F1. An F2 population is produced by selfing one or several F1""s or by intercrossing two F1""s (sib mating). Selection of the best individuals may begin in the F2 population; then, beginning in the F3, the best individuals in the successive filial generations are selected. Replicated testing of families can begin in the F4 generation to improve the effectiveness of selection for traits with low heritability. At an advanced stage of inbreeding (i.e., F6 and F7), the best varieties or mixtures of phenotypically similar varieties are tested for potential release as new varieties.
Backcross breeding has been used to transfer genes for simply inherited, highly heritable traits from a donor parent into a desirable homozygous variety that is utilized as the recurrent parent. The source of the traits to be transferred is called the donor parent. After the initial cross, individuals possessing the desired trait or traits of the donor parent are selected and then repeatedly crossed (backcrossed) with the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., variety) plus the desirable trait or traits transferred from the donor parent. This approach has been used extensively for breeding disease resistant varieties.
Each soybean breeding program should include a periodic, objective evaluation of the efficiency of the breeding procedure. Evaluation criteria vary depending on the goal and objectives, but should include gain from selection per year based on comparisons to an appropriate standard, overall value of the advanced breeding varieties, and number of successful varieties produced per unit of input (e.g., per year, per dollar expended, etc.).
Various recurrent selection techniques are used to improve quantitatively inherited traits controlled by numerous genes. The use of recurrent selection in self-pollinating crops depends on the ease of pollination and the number of hybrid offspring from each successful cross.
Mass selection and recurrent selection can be used to improve populations of either self- or cross-pollinated crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population in which further cycles of selection are continued.
The single-seed descent procedure in the strict sense refers to planting a segregating population, harvesting a sample of one seed per plant, and using the one-seed sample to plant the next generation. When the population has been advanced from the F2 to the desired level of inbreeding, the plants from which varieties are derived will each trace to different F2 individuals. The number of plants in a population declines each generation due to failure of some seeds to germinate or some plants to produce at least one seed. As a result, not all of the F2 plants originally sampled in the population will be represented by a progeny when generation advance is completed.
In a multiple-seed procedure, soybean breeders commonly harvest one or more pods from each plant in a population and thresh them together to form a bulk. Part of the bulk is used to plant the next generation and part is put in reserve. The procedure has been referred to as modified single-seed descent or the pod-bulk technique.
The multiple-seed procedure has been used to save labor at harvest. It is considerably faster to thresh pods with a machine than to remove one seed from each by hand for the single-seed procedure. The multiple-seed procedure also makes it possible to plant the same number of seeds of a population each generation of inbreeding. Enough seeds are harvested to make up for those plants that did not germinate or produce seed.
Molecular markers which includes markers identified through the use of techniques such as such Isozyme Electrophoresis, Restriction Fragment Length Polymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats (SSRs), and Single Nucleotide Polymorphisms (SNPs) may be used in plant breeding methods. One use of molecular markers is Quantitative Trait Loci (QTL) mapping. QTL mapping is the use of markers, which are known to be closely linked to alleles that have measurable effects on a quantitative trait. Selection in the breeding process is based upon the accumulation of markers linked to the positive effecting alleles and/or the elimination of the markers linked to the negative effecting alleles from the plant""s genome.
Molecular markers can also be used during the breeding process for the selection of qualitative traits. For example, markers closely linked to alleles or markers containing sequences within the actual alleles of interest can be used to select plants that contain the alleles of interest during a backcrossing breeding program. For example, molecular markers are often used in soybean breeding for selection of the trait of resistance to soybean cyst nematode, See, U.S. Pat. No. 6,162,967. The markers can also be used to select for the genome of the recurrent parent and against the markers of the donor parent. Using this procedure can minimize the amount of genome from the donor parent that remains in the selected plants. It can also be used to reduce the number of crosses back to the recurrent parent needed in a backcrossing program. The use of molecular markers in the selection process is often called Genetic Marker Enhanced Selection. Molecular markers may also be used to identify and exclude certain sources of germplasm as parental varieties or ancestors of a plant by providing a means of tracking genetic profiles through crosses as discussed more fully hereinafter.
The production of double haploids can also be used for the development of homozygous varieties in the breeding program. Double haploids are produced by the doubling of a set of chromosomes (1N) from a heterozygous plant to produce a completely homozygous individual. For example. See Wan et al., xe2x80x9cEfficient Production of Doubled Haploid Plants Through Colchicine Treatment of Anther-Derived Maize callusxe2x80x9d Theoretical and Applied genetics, 77:889-892, 1989. This can be advantageous because the process omits the generations of selfing needed to obtain a homozygous plant from a heterozygous source.
Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard, Principles of Plant Breeding, 1960; Simmonds, Principles of Crop Improvement, 1979; Sneep et al., 1979; Fehr, xe2x80x9cBreeding Methods for Cultivar Developmentxe2x80x9d, Chapter 7, Soybean Improvement, Production and Uses, 2nd ed., Wilcox editor, 1987).
Promising advanced breeding varieties are thoroughly tested and compared to appropriate standards in environments representative of the commercial target area(s). The best varieties are candidates for new commercial varieties; those still deficient in a few traits may be used as parents to produce new populations for further selection.
A most difficult task is the identification of individuals that are genetically superior, because for most traits the true genotypic value is masked by other confounding plant traits or environmental factors. One method of identifying a superior plant is to observe its performance relative to other experimental plants and to a widely grown standard variety. Generally a single observation is inconclusive, so replicated observations are required to provide a better estimate of its genetic worth.
Thus, even if the entire genotypes of the parents of the breeding cross were characterized and a desired genotype known, only a few if any individuals having the desired genotype may be found in a large segregating F2 population. It would be very unlikely that a breeder of ordinary skill in the art would be able to recreate the same variety twice from the very same original parents as the breeder is unable to direct how the genomes combine or how they will interact with the environmental conditions. This unpredictability results in the expenditure of large amounts of research resources in the development of a superior new soybean variety. Breeders use various methods to help determine which plants should be selected from the segregating populations and ultimately which varieties will be used for commercialization. In addition to the knowledge of the germplasm and other skills the breeder uses, a part of the selection process is dependent on experimental design coupled with the use of statistical analysis. Experimental design and statistical analysis are used to help determine which plants, which family of plants, and finally which varieties are significantly better or different for one or more traits of interest. Experimental design methods are used to assess error so that differences between two varieties can be more accurately determined. Statistical analysis includes the calculation of mean values, determination of the statistical significance of the sources of variation, and the calculation of the appropriate variance components. Either a five or a one percent significance levels is customarily used to determine whether a difference that occurs for a given trait is real or due to the environment or experimental error.
One of ordinary skill in the art of plant breeding would know how to evaluate the traits of two plant varieties to determine if there is no significant difference between the two traits expressed by those varieties. For example, see Fehr, Walt, Principles of Cultivar Development, p. 261-286 (1987) which is incorporated herein by reference. Mean trait values may be used to determine whether trait differences are significant, and preferably the traits are measured on plants grown under the same environmental conditions. Once such a variety is developed its value is substantial since it is important to advance the germplasm base as a whole in order to maintain or improve traits such as yield, disease resistance, pest resistance, and plant performance in extreme weather conditions.
The goal of soybean breeding is to develop new, unique and superior soybean varieties. In practical application of a chosen soybean breeding program, the breeder initially selects and crosses two or more parental varieties, followed by repeated selfing and selection, producing many new genetic combinations. Two breeders will never develop the same variety, or even very similar varieties, having the same soybean traits.
Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic and soil conditions, and further selections are then made during and at the end of the growing season.
Proper testing should detect major faults and establish the level of superiority or improvement over current varieties. In addition to showing superior performance, there must be a demand for a new variety. The new variety must be compatible with industry standards, or must create a new market. The introduction of a new variety may incur additional costs to the seed producer, the grower, processor and consumer, for special advertising and marketing, altered seed and commercial production practices, and new product utilization. The testing preceding release of a new variety should take into consideration research and development costs as well as technical superiority of the final variety. For seed-propagated varieties, it must be feasible to produce seed easily and economically. Preferably residual heterozygosity should not exceed 5%.
These processes, which lead to the final step of marketing and distribution, can take from six to twelve years from the time the first cross is made. Therefore, development of new varieties is a time-consuming process that requires precise forward planning, efficient use of resources, and a minimum of changes in direction.
Soybean (Glycine max), is an important and valuable field crop. Thus, a continuing goal of soybean breeders is to develop stable, high yielding soybean varieties that are agronomically sound. The reasons for this goal are obviously to maximize the amount of grain produced on the land used and to supply food for both animals and humans. To accomplish this goal, the soybean breeder must select and develop soybean plants that have the traits that result in superior varieties.
Pioneer soybean research staff creates over 500,000 potential new varieties each year. Of those new varieties, less than 50 and more commonly less than 25 are actually selected for commercial use.
According to the invention, there is provided a novel soybean variety, designated 91B03. This invention thus relates to the seeds of soybean variety 91B03, to the plants of soybean 91B03 to plant parts of soybean variety 91B03 and to methods for producing a soybean plant produced by crossing soybean variety 91B03 with another soybean plant, using 91B03 as either the male or the female parent. This invention also relates to methods for producing a soybean plant containing in its genetic material one or more transgenes and to the transgenic soybean plants and plant parts produced by that methods. This invention also relates to soybean varieties or breeding varieties and plant parts derived from soybean variety 91B03, to methods for producing other soybean varieties, lines or plant parts derived from soybean variety 91B03 and to the soybean plants, varieties, and their parts derived from use of those methods. This invention further relates to soybean seeds, plants, and plant parts produced by crossing the soybean variety 91B03 with another soybean variety. Soybean variety 91B03 demonstrates a unique combination of traits, which include high yield potential, good iron-deficiency chlorosis tolerance, multi-race Phytophthora root rot resistance, exceptional standability, exceptional tolerance to pod shattering, and a substantial degree of glyphosate resistance. Soybean variety 91B03 is in the relative maturity group I, sub-group 0, and is particularly adapted to Canada, and the North Central and Eastern areas of the United States.
Definitions
Certain definitions used in the specification are provided below. Also in the examples which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:
ALLELE=any of one or more alternative forms of a genetic sequence. In a diploid cell or organism, the two alleles of a given sequence occupy corresponding loci on a pair of homologous chromosomes.
BACKCROSSING=Process in which a breeder crosses a progeny variety back to one of the parental genotypes one or more times.
BREEDING=The genetic manipulation of living organisms.
BU/A=Bushels per Acre. The seed yield in bushels/acre is the actual yield of the grain at harvest.
BSR=Brown Stem Rot Tolerance. This is a visual disease score from 1 to 9 comparing all genotypes in a given test. The score is based on leaf symptoms of yellowing and necrosis caused by brown stem rot. A score of 9 indicates no symptoms. Visual scores range down to a score of 1 which indicates severe symptoms of leaf yellowing and necrosis.
CNKR=Stem Canker Tolerance. This is a visual disease score from 1 to 9 comparing all genotypes in a given test. The score is based upon premature plant death. A score of 9 indicates no symptoms, whereas a score of 1 indicates the entire experimental unit died very early.
COTYLEDON=A cotyledon is a type of seed leaf. The cotyledon contains the food storage tissues of the seed. ELITE VARIETY=A variety that is sufficiently homozygous and homogeneous to be used for commercial grain production. An elite variety may also be used in further breeding.
EMBRYO=The embryo is the small plant contained within a mature seed.
EMGSC=Emergence Score. The percentage of emerged plants in a plot respective to the number of seeds planted.
F3=This symbol denotes a generation resulting from the selfing of the F2 generation along with selection for type and rogueing of off-types. The xe2x80x9cFxe2x80x9d number is a term commonly used in genetics, and designates the number of the filial generation. The xe2x80x9cF3xe2x80x9d generation denotes the offspring resulting from the selfing or self mating of members of the generation having the next lower xe2x80x9cFxe2x80x9d number, viz. the F2 generation.
FEC=Iron-deficiency Chlorosis. Plants are scored 1 to 9 based on visual observations. A score of 1 indicates the plants are dead or dying from iron-deficiency chlorosis, a score of 5 means plants have intermediate health with some leaf yellowing and a score of 9 means no stunting of the plants or yellowing of the leaves. Plots are usually scored in mid July.
FECL=Iron-deficiency Chlorosis. Plants are scored 1 to 9 based on visual observations. A score of 1 indicates the plants are dead or dying from iron-deficiency chlorosis, a score of 5 means plants have intermediate health with some leaf yellowing and a score of 9 means no stunting of the plants or yellowing of the leaves. Plots are scored around mid August.
FEY=Frogeye Tolerance. This is a visual disease score from 1 to 9 comparing all genotypes in a given test. The score is based upon leaf lesions. A score of 9 indicates no lesions, whereas a score of 1 indicates severe leaf necrosis.
GENOTYPE=Refers to the genetic constitution of a cell or organism.
HABIT=This refers to the physical appearance of a plant. It can be determinate, semi-determinate, intermediate, or indeterminate. In soybeans, indeterminate varieties are those in which stem growth is not limited by formation of a reproductive structure (i.e., flowers, pods and seeds) and hence growth continues throughout flowering and during part of pod filling. The main stem will develop and set pods over a prolonged period under favorable conditions. In soybeans, determinate varieties are those in which stem growth ceases at flowering time. Most flowers develop simultaneously, and most pods fill at approximately the same time. The terms semi-determinate and intermediate are also used to describe plant habit and are defined in Bernard, R. L. 1972. xe2x80x9cTwo genes affecting stem termination in soybeans.xe2x80x9d Crop Science 12:235-239; Woodworth, C. M. 1932. xe2x80x9cGenetics and breeding in the improvement of the soybean.xe2x80x9d Bull. Agric. Exp. Stn. (Illinois) 384:297-404; Woodworth, C. M. 1933. xe2x80x9cGenetics of the soybean.xe2x80x9d J. Am. Soc. Agron. 25:36-51.
HGT=Plant Height. Plant height is taken from the top of the soil to top pod of the plant and is measured in inches.
HILUM=This refers to the scar left on the seed which marks the place where the seed was attached to the pod prior to it (the seed) being harvested.
HYPL=Hypocotyl Elongation. This score indicates the ability of the seed to emerge when planted 3xe2x80x3 deep in sand pots and with a controlled temperature of 25xc2x0 C. The number of plants that emerge each day are counted. Based on this data, each genotype is given a 1 to 9 score based on its rate of emergence and percent of emergence. A score of 9 indicates an excellent rate and percent of emergence, an intermediate score of 5 indicates average ratings and a 1 score indicates a very poor rate and percent of emergence.
HYPOCOTYL=A hypocotyl is the portion of an embryo or seedling between the cotyledons and the root. Therefore, it can be considered a transition zone between shoot and root.
LDGSEV=Lodging Resistance. Lodging is rated on a scale of 1 to 9. A score of 9 indicates erect plants. A score of 5 indicates plants are leaning at a 45xc2x0 angle in relation to the ground and a score of 1 indicates plants are laying on the ground.
LEAFLETS=These are part of the plant shoot, and they manufacture food for the plant by the process of photosynthesis.
LINKAGE=Refers to a phenomenon wherein alleles on the same chromosome tend to segregate together more often than expected by chance if their transmission was independent.
LINKAGE DISEQUILIBRIUM=Refers to a phenomenon wherein alleles tend to remain together in linkage groups when segregating from parents to offspring, with a greater frequency than expected from their individual frequencies.
LLE=Linoleic Acid Percent. Linoleic acid is one of the five most abundant fatty acids in soybean seeds. It is measured by gas chromatography and is reported as a percent of the total oil content.
LLN=Linolenic Acid Percent. Linolenic acid is one of the five most abundant fatty acids in soybean seeds. It is measured by gas chromatography and is reported as a percent of the total oil content.
MAT ABS=Absolute Maturity. This term is defined as the length of time from planting to complete physiological development (maturity). The period from planting until maturity is reached is measured in days, usually in comparison to one or more standard varieties. Plants are considered mature when 95% of the pods have reached their mature color.
MATURITY GROUP=This refers to an agreed-on industry division of groups of varieties, based on the zones in which they are adapted primarily according to day length or latitude. They consist of very long day length varieties (Groups 000, 00, 0), and extend to very short day length varieties (Groups VII, VIII, IX, X).
OIL=Oil Percent. Soybean seeds contain a considerable amount of oil. Oil is measured by NIR spectrophotometry, and is reported on an as is percentage basis.
OLC=Oleic Acid Percent. Oleic acid is one of the five most abundant fatty acids in soybean seeds. It is measured by gas chromatography and is reported as a percent of the total oil content.
PEDIGREE DISTANCE=Relationship among generations based on their ancestral links as evidenced in pedigrees. May be measured by the distance of the pedigree from a given starting point in the ancestry. PLM=Palmitic Acid Percent. Palmitic acid is one of the five most abundant fatty acids in soybean seeds. It is measured by gas chromatography and is reported as a percent of the total oil content.
POD=This refers to the fruit of a soybean plant. It consists of the hull or shell (pericarp) and the soybean seeds.
PRT=Phytophthora Tolerance. Tolerance to Phytophthora root rot is rated on a scale of 1 to 9, with a score of 9 being the best or highest tolerance ranging down to a score of 1 which indicates the plants have no tolerance to Phytophthora.
PRMMAT=Predicted Relative Maturity. Soybean maturities are divided into relative maturity groups. In the United States the most common maturity groups are 00 through VIII. Within maturity groups 00 through V are sub-groups. A sub-group is a tenth of a relative maturity group. Within narrow comparisons, the difference of a tenth of a relative maturity group equates very roughly to a day difference in maturity at harvest.
PRO=Protein Percent. Soybean seeds contain a considerable amount of protein. Protein is generally measured by NIR spectrophotometry, and is reported on an as is percentage basis.
PUBESCENCE=This refers to a covering of very fine hairs closely arranged on the leaves, stems and pods of the soybean plant.
RKI=Root-knot Nematode, Southern. This is a visual disease score from 1 to 9 comparing all genotypes in a given test. The score is based upon digging plants to visually score the roots for presence or absence of galling. A score of 9 indicates that there is no galling of the roots, a score of 1 indicates large severe galling cover most of the root system which results in pre-mature death from decomposing of the root system.
RKA=Root-knot Nematode, Peanut. This is a visual disease score from 1 to 9 comparing all genotypes in a given test. The score is based upon digging plants to look at the roots for presence or absence of galling. A score of 9 indicates that there is no galling of the roots, a score of 1 indicates large severe galling cover most of the root system which results in pre-mature death from decomposing of the root system.
SD VIG=Seedling Vigor. The score is based on the speed of emergence of the plants within a plot relative to other plots within an experiment. A score of 9 indicates that 90% of plants growing have expanded first leaves. A score of 1 indicates no plants have expanded first leaves.
SDS=Sudden Death Syndrome. Tolerance to Sudden Death Syndrome is rated on a scale of 1 to 9, with a score of 1 being very susceptible ranging up to a score of 9 being tolerant.
S/LB=Seeds per Pound. Soybean seeds vary in seed size, therefore, the is number of seeds required to make up one pound also varies. This affects the pounds of seed required to plant a given area, and can also impact end uses.
SHATTR=Shattering. This refers to the amount of pod dehiscence prior to harvest. Pod dehiscence involves seeds falling from the pods to the soil. This is a visual score from 1 to 9 comparing all genotypes within a given test. A score of 9 means pods have not opened and no seeds have fallen out. A score of 5 indicates approximately 50% of the pods have opened, with seeds falling to the ground and a score of 1 indicates 100% of the pods are opened.
SHOOTS=These are a portion of the body of the plant. They consist of stems, petioles and leaves.
STC=Stearic Acid Percent. Stearic acid is one of the five most abundant fatty acids in soybean seeds. It is measured by gas chromatography and is reported as a percent of the total oil content.
WH MD=White Mold Tolerance. This is a visual disease score from 1 to 9 comparing all genotypes in a given test. The score is based upon observations of mycelial growth and death of plants. A score of 9 indicates no symptoms. Visual scores of 1 indicate complete death of the experimental unit.
Definitions for Area of Adaptability
When referring to area of adaptability, such term is used to describe the location with the environmental conditions that would be well suited for this soybean variety. Area of adaptability is based on a number of factors, for example: days to maturity, insect resistance, disease resistance, and drought resistance. Area of adaptability does not indicate that the soybean variety will grow in every location within the area of adaptability or that it will not grow outside the area.
Midwest: Iowa and Missouri
Heartland: Illinois and the western half of Indiana
Plains: 2/3 of the eastern parts of South Dakota and Nebraska
North Central: Minnesota, Wisconsin, the Upper Peninsula of Michigan, and the eastern half of North Dakota
Mideast: Michigan, Ohio, and the eastern half of Indiana
Eastern: Pennsylvania, Delaware, Maryland, Rhode Island, New Jersey, Connecticut, Massachusetts, New York, Vermont, and Maine
Southern: Virginia, West Virginia, Tennessee, Kentucky, Arkansas, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, and Louisiana
Western: Texas, Kansas, Colorado, Oklahoma, New Mexico, Arizona, Utah, Nevada, California, Washington, Oregon, Montana, Idaho, Wyoming, the western half of North Dakota, and the western 1/3 South Dakota and Nebraska
PMG infested soils: soils containing Phytophthora megasperma 
Narrow rows: 7xe2x80x3 and 15xe2x80x3 row spacing
High yield environments: areas which lack normal stress for example they have sufficient rainfall, water drainage, low disease pressure, and low weed pressure Tough environments: areas which have stress challenges, opposite of a high yield environment